Mountain Lion improperly ejects external disks

Has anybody else had this problem? Ever since I updated to Mountain Lion, my external hard drives are periodically and seemingly randomly ejected, giving me an error message about improperly ejected disks. I have two drives, daisy-chained in firewire on a 2012 iMac.

I have a similar problem; however, when I reboot my MacBook Pro (or shutdown and restart later), one of the drives will be reported by Mac OS X that it cannot be repaired. I have wiped, repartitioned and reformated a couple of times and this keeps happening.

I have noticed that if I manually unmount (i.e. eject) the drive, prior to shutting down the drive, I don't have this problem. Once in a while, however, the drive spontaneously unmounts or I cannot eject the drive at all and have to reboot - when the latter happens, the drive is corrupted.

Do the drives have their own power sources? What baran are they? Some are not playing well with Macs especially USB 3.0 that are connected as USB 2.0. Do the FireWire drives show up in the list of Disk Utility? Are they formatted correctly?

4. I have run Disk Utility on both, but just recently and don't yet know if that was a solution. The one that I use for Time Machine couldn't repair permissions, due to that command being grayed out. Not sure why?

5. the problem onlly started when I switched to Mountain Lion, therefore I suspect OS problems.

I will try switching the order of the daisy-chain, and see if that has any effect.

I, too, am having hard drive problems with my new Macbook Pro 15" Retina, specifically it won't unmount or eject one of my USB drives. I can shut-down the computer and remove the drive, but that's the only way to eject it without a "force quit." I also can't run Disk Utility on it because it won't unmount.

Yes, after running with it for a few days, the disk repair seems to have helped. At least, the disks have not been ejected since I repaired them. Interestingly, I am still getting occasional "disk ejected improperly" messages, but the disks themselves remain on the desktop. Something is still wrong, but it doesn't seem to affect workings of the external HDs, at least.

Same thing over here. Only seems to be an issue with my USB drives. Happens about 1 out of 5 times I use the spotlight shortcut. I have heard it is a problem with the drive controller but havent been able to fix. Also seem to be having issues with my drives running really hot since updating.

I am having the same problem with a Seagate 3 TB Thunderbolt drive. Drive gets improperly ejected, then wont show up on desktop or disc utility until I reboot. My Firewire external drive is fine. Even though not showing up on desktop, System Info still shows drive connected via Thunderbolt port. And it will eject randomly, not just at sleep. So far no problems when actively writing to or reading from drive. Apple tech support tries zapping PRAM, didn't help.

More Like This

Retrieving data ...

This site contains user submitted content, comments and opinions and is for informational purposes only.
Apple may provide or recommend responses as a possible solution based on the information provided; every potential issue may involve several factors not detailed in the conversations captured in an electronic forum and Apple can therefore provide no guarantee as to the efficacy of any proposed solutions on the community forums.
Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.